Access to Astronomical Catalogues

← Click to display the menu
J/A+A/601/A80       LABOCA 345GHz observations of Sgr A*      (Subroweit+, 2017)

Submillimeter and radio variability of Sagittarius A*. A statistical analysis. Subroweit M., Garcia-Marin M., Eckart A., Borkar A., Valencia-S. M., Witzel G., Shahzamanian B., Straubmeier C. <Astron. Astrophys. 601, A80 (2017)> =2017A&A...601A..80S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Radio sources ; Millimetric/submm sources Keywords: black hole physics - galaxies: statistics - Galaxy: nucleus - Galaxy: nucleus - radio continuum: general - submillimeter: general - Galaxy: center Abstract: We report on a statistical analysis of the 345GHz submillimeter (submm) and 100GHz radio flux density distribution of Sagittarius A* (Sgr A*). The submm data set consists of 345GHz data obtained from different Large Apex Bolometer Camera (LABOCA) campaigns between 2008 and 2014, and additional literature data from 2004 to 2009 at comparable wavelengths. The radio observations were carried out with the Australia Telescope Compact Array (ATCA) between 2010 and 2014. We used a combined maximum likelihood estimator (MLE) and Kolmogorov-Smirnov (KS) statistics method to test for a possible power-law distribution in the high flux density excursions (flares) at both wavebands. We find that both flux density distributions can be described by a shifted power-law of the form p(x)∝(x-S) with α∼4 (submm: α=4.0±1.7, radio: α=4.7±0.8). The same power-law index was previously found for the near-infrared (NIR) flux density distribution. These results may strengthen our preferred flare emission model: a combined synchrotron self-Compton (SSC) and adiabatically expanding self-absorbed synchrotron blob model where the flaring activity across all wavebands stem from the same source components and the variable emission can be described by a single state red noise process. Within the framework of the expanding blob model the similarity of the radio and the submm flux density distribution may also narrow down possible initial synchrotron turnover ν0 to be mainly around 350GHz and possible expansion velocities vexp to be predominantly around 0.01c. Description: LABOCA is a multi-channel bolometer array, consisting of 295 channels, installed at the APEX telescope. APEX is a 12m radio telescope located at the Llano de Chajnantor Observatory 50km east of San Pedro de Atacama in northern Chile. It is situated at an altitude of 5014m. LABOCA operates in the 345GHz (870um) atmospheric window and has a bandwidth of 60GHz. The beam shape can be described as a circular Gaussian with a full width half maximum (FWHM)∼19". Photometry data of the submm APEX/LABOCA observations from 2008 to 2014. Objects: ---------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------- 17 45 40.04 -29 00 28.2 Sgr A* = NAME Sgr A* ---------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file photom.dat 41 792 APEX/LABOCA observations of the Galactic Center
See also: J/A+A/534/A117 : NIR polarimetry of sources near SgrA* (Buchholz+, 2011) J/MNRAS/428/2731 : SgrA* emission at 7mm (Beaklini+, 2013) J/ApJ/820/90 : 4yr 1.3mm VLBI observations of SgrA* with EHT (Fish+, 2016) Byte-by-byte Description of file: photom.dat
Bytes Format Units Label Explanations
1- 20 F20.14 d MJD Time of observation 22- 41 F20.18 Jy Flux LABOCA 345GHz flux density
Acknowledgements: Matthias Subroweit, subroweit(at)
(End) Patricia Vannier [CDS] 24-Apr-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service